/sigh
Ok.
The only similarity between Sayaka's sabre-like katana and Souta's sabres is that they are swords. There are already multiple characters in this RP with swords; do you have a problem with them too? Take a look at the style of fighting; Sayaka uses her sword like a katana. Short, chopping slashes, jabs and stabs. Souta uses both swords in a form of constant pirouette, moving slowly back and forth as he makes long, sweeping slashes and parrying blows. I apologise if that wasn't obvious enough. This is also how he is better suited to fighting other Magi; Wraiths aren't human sized enemies that can be countered easily, Magi are. Does that mean he's OP? No, just that he's marginally better suited to one kind of fight than another.

Originality isn't a bad thing, but it can get daft, either in the way it 'borrows' from other series or gets so far away from the canon that it doesn't make sense anymore. At the end of the day, what's wrong with the basics? The bleak personality is not a bad thing; it means that he is dark, cynical and jaded. This makes for a surprisingly good character for group interaction if played right. If everyone in the group is a positive thinker, it can get stale fast. Some emo is needed to balance the conversation.

If his combat style is really, [i]really[/i] that OP sounding, then contemplate this; as he fights, he gets angry. As he gets angrier, he drains more magic and gains more despair. The more despair he gains, the closer he is to death. Ergo, his style of combat is utterly self-destructive. In a bad way. As for the social side of things, reread the CS: he does care, he just hides it well. If he didn't care about others, why would he have left Tokyo after his first fight? The entire rational behind him being a traveling Magi is to avoid the turf wars fought between Magi in the big urban centres, in order to avoid the possibility of killing or being killed by other Magi. Yes, being distrustful would normally be an advantage and it would have served him well elsewhere. But in this RP, Souta would need to get on with the other characters. Not trusting any of them is a serious disadvantage for him.

What else have I missed... Oh yeah. Magi on the BRINK of despair are not dead, just very, very close. Like Souta and this links back to the combat style thing. If he does fight when this close to despair, he will likely blow too much magic and die. Therefore, he will not. Auto-balance, right there. As for interesting, well... that's a matter of opinion. I think his style would look great, but if you disagree then that's your choice. But I wouldn't comment if I found your character to be boring. Different points of view and all that.